I really wanted to love these! The idea is awesome, a pair of tweezers that replaces your multimeter and can quickly identify an unknown tiny SMD component and give you an accurate readout on its little OLED display.
The fit and finish - It's clearly made to a price point. My pair had the arms slightly crooked so the contacts didn't meet up until they were fully closed. Looking at other reviews, I think I got a bad pair and many of my gripes may originate from this defect.
Measuring components in circuit - This goes for any meter, not just the DT71. You really can't reliably measure a components value in circuit (there are exceptions, but as a general rule, the reading will be off) And that is the entire purpose of these tweezers, to measure SMD in circuit. If you were to try to measure a loose 0805 SMD resistor, there's a good chance of it getting launched across the room never to be seen again (probably due to my wonky arms but mostly due to the springy nature of the tweezers). So for the intended purpose, measuring component values in circuit it falls short.
Voltage measuring - No problems here and it was actually really convenient. Clip it onto a SMD cap and you'll get an accurate voltage readout. If it read negative voltage (if you have the tweezers around the wrong way) it would be perfect, instead you get a warning that its a negative value and you need to change polarity. Any other meter seems to be able to handle this just fine.
Frequency measuring - No issues here on a clean signal either. Was as accurate as my full size meter.
Resistance measuring - Again the wonky arms gave me grief but once you get a good grip on the resistor, its accurate though a little slow to autorange and get you a readout.
Capacitance/Inductance - Same again, wonky arms but was ultimately accurate albeit a little slow.
What would be super convenient is a logic level detector, something that quickly shows Low, High or changing state. You can do that now using the voltage measurement but a faster mode of indication would make this super helpful. I wonder if this is open source too and we code code that in? A buzzer would be nice too.
So ultimately, its fine as a multimeter. Not that handy for SMD in circuit but it is still handy to identify loose resistors, diodes, caps, transistors and caps that don't have markings. It's handy for measuring voltages across SMD caps. It's handy when measuring an oscillators frequency. All of this could be done with a cheaper multimeter though at least this will do it one handed!
I haven't tested the signal generator mode but no doubt it works as advertised.
Oh and they say there is a firmware update coming.